Assassination by crossbow, refueling homemade planes in mid-air, mother and daughter seduction—Allied spy Tommy Sneum did all of these during World War II, and nearly died on a frozen sea returning with vital information for Britain about Hitler's radar system. For his trouble, he was imprisoned in Brixton as a suspected double agent. Sneum cheated the hangman, but it is only with the publication of this book that he can finally be celebrated as, in the words of Winston Churchill's chief of scientific intelligence, "one of the true heroes of World War II." Mark Ryan's biography is based in large part on extensive interviews with Sneum.